Camera devices that can capture a video at a high frame rate have been proposed (for example, see Patent Document 1). The camera device acquires a video signal for a viewfinder display by converting the high-frame-rate video signal into a normal-frame-rate video signal (a normal speed video signal).
A function to highlight the edge signal (high-frequency components) extracted from the video signal for a viewfinder display in order to use the edge signal as a marker to facilitate the operation of manually bringing the camera into focus with the viewfinder (for example, the PEAKING function, or the VF-DETAIL function) has been known (for example, see Patent Document 2). Using this technique can check whether the camera is in focus by checking the highlighted edge because there is a drastic change in the signal level of the part in focus (edge).